Head mounted display and method

Abstract

A system for displaying a mobile device screen comprises a head mounted display for displaying a first content to a user, a video camera mounted on the head mounted display, the video camera operable to capture a video image of a scene in front of the user, a region detection processor operable to detect a region of the captured video image comprising a mobile device screen, and an image processor operable to replace a corresponding region of the displayed first content in the head mounted display with the detected region of the captured video image comprising the mobile device screen.

The invention claimed is: 
     
       1. A system for displaying a mobile device screen, comprising:
 a head mounted display for displaying a first content to a user; 
 a video camera mounted on the head mounted display, the video camera operable to capture a video image of a scene in front of the user; 
 a region detection processor operable to detect a screen region of the captured video image comprising a mobile device screen; and 
 an image processor operable to replace a corresponding region of the displayed first content in the head mounted display with the detected screen region of the captured video image comprising the mobile device screen. 
 
     
     
       2. The system of  claim 1 , in which the region detection processor is operable to detect the screen region of the captured video image comprising a mobile device screen responsive to the brightness of a candidate screen region in the captured image. 
     
     
       3. The system of  claim 1 , comprising
 a distance detection processor, and in which 
 the region detection processor is operable to detect the screen region of the captured video image comprising the screen responsive to the distance of a candidate screen region from the video camera. 
 
     
     
       4. The system of  claim 1 , comprising
 an image correlator arranged to discount a candidate screen region within the captured video image that corresponds to an image currently being output to a secondary display by the source of the first content. 
 
     
     
       5. The system of  claim 1 , comprising
 a control correlator arranged to discount as a candidate screen region any light source having one or more selected from the list consisting of: 
 i. a colour; and 
 ii. a position, 
 corresponding to a light emitting control device currently associated with the first content source. 
 
     
     
       6. The system of  claim 1 , comprising
 a calibration processor arranged to record the relative position with respect to the head mounted display of light sources within the captured video images for a first predetermined period of time, and to discount these light sources as candidate screen regions within subsequently captured video images. 
 
     
     
       7. The system of  claim 1 , comprising
 an orientation detector, and in which 
 the region detection processor is operable to only detect a screen region of the captured video image comprising a mobile device screen when the head mounted display is facing below a predetermined angle with respect to the horizontal. 
 
     
     
       8. The system of  claim 1 , in which
 the image processor is operable to select the region of the displayed first content in the head mounted display to be replaced with the corresponding screen region of the captured video image by transposing the location of the screen within the captured video image to a corresponding location within a display of the head mounted display. 
 
     
     
       9. The system of  claim 8 , in which
 if the head mounted display has a stereoscopic pair of displays, the image processor is adapted to select a region for each display with a relative offset to generate a predetermined parallax. 
 
     
     
       10. The system of  claim 9 , in which
 the relative offset is one selected from the list consisting of: 
 i. a predetermined offset corresponding to an average distance at which a user holds a mobile device away from the video camera during normal use; and 
 ii. a distance value obtained by a distance detection processor. 
 
     
     
       11. The system of  claim 9 , in which
 the video camera is a stereoscopic video camera; and 
 the relative offset is a function of the relative offset of the screen within the stereoscopic images from the video camera. 
 
     
     
       12. A method of displaying a mobile device screen, comprising the steps of:
 displaying a first content to a user through a head mounted display; 
 capturing a scene in front of the user from a video camera mounted on the head mounted display; 
 detecting a screen region of the captured video image comprising a mobile device screen; and 
 replacing a corresponding region of the displayed first content in the head mounted display with the detected screen region of the captured video image comprising the mobile device screen. 
 
     
     
       13. The method of  claim 12 , in which the detecting step comprises one or more selected from the list consisting of:
 i. selecting a candidate screen region of the video image responsive to the comparative brightness of the image to a background region of the video image; 
 ii. selecting a candidate screen region of the video image responsive to a detected distance of the region from the video camera; 
 iii. discounting a candidate screen region of the video image that correlates with known output from the source of the first content; 
 iv. discounting a candidate screen region of the video image that has a colour and/or position corresponding to a known light emitting control device currently associated with the first content source; and 
 v. discounting a candidate screen region of the video image having a position corresponding to a light source identified during a calibration step. 
 
     
     
       14. The method of  claim 12 , comprising the step of:
 detecting an orientation of the head mounted display; 
 and in which the step of detecting a screen region of the captured video image comprising a mobile device screen is responsive to whether the head mounted display is facing below a predetermined angle with respect to the horizontal. 
 
     
     
       15. A non-transitory computer readable medium having computer executable instructions adapted to cause a computer system to perform the method of  claim 12 .